Fire alarm



July 6, 1937. J. .Y. LAMBERT FIRE ALARM Filed March 15, 1936 INVENTOR VJ. K. fifBEfiT ATTORNEYS Patented July 6, 1937 FIRE ALARM John Y.Lambert, Syracuse, N. Y.

Application March 13 3 Claims.

lhis invention relates to fire alarm mechanisms, and more particularly,to those types of alarm devices which are primarily adapted toautomatically give an audible signal in the event that a fire starts insome place where the fire is not likely to be promptly observed.

One of the primary objects of the invention is to provide a simple,efficient and reliable, selfcontained automatic alarm unit which may bemanufactured at comparatively low cost so as to come within the means ofthe average person. In other Words, it is my aim to provide an alarmunit which is readily adaptable for common usage, as in ordinarydwellings, and eliminating the usual complications and expense attachedto the installation of fire alarms such as have heretofore beenavailable. Of course, my alarm unit may be installed any place where afire is liable to occur, as it is not limited to use in dwellings.

A further object of the invention is to provide an improvedspring-actuated alarm unit which is normally restrained from operationby one or more fusible links, which will melt quickly when a fire breaksout and thereby release the alarm trip so that one or more signaldevices, preferably of an audible character, Will be soundedautomatically.

Another object of the invention is to provide an improved means forfacilitating the replacement of the fusible link or links forming a partof the alarm apparatus, and thereby enabling the alarm apparatus to bereset quickly and by a very simple operation.

A still further object of the invention is to provide a means forindicating whether or not the alarm has been tripped, so that if asignal has been given without attracting attention, the necessity forresetting the alarm will be made apparent, preferably through mereobservation of a suitable signal or indicator member which becomesvisible only when the alarm is set off, and remains visible until thealarm is reset.

Other and further objects and advantages of the invention will behereinafter described and the novel features thereof defined by theappended claims.

In the drawing:

Figure 1 is a front elevation of an alarm unit embodying the improvedfeatures of my invention, a portion of the front wall of the housing orcas ing being broken away to expose the interior mechanism;

Figure 2 is a sectional view taken approximately on the line 22 ofFigure 1, looking in the direction of the arrows; and

, 1936, Serial No. 68,727

Figure 3 is a fragmentary detail view of a modified fusible restraininglink arrangement, as viewed in looking downwardly at the upper lefthandcorner of the alarm unit illustrated in Figure 1.

Like reference characters designate corresponding parts in the severalfigures of the drawing, wherein I designates a plate or base havingsuitable apertures Z, 2 therein to enable the plate to be secured to awall or other convenient support, as by means of screws or nails. Uponthis plate I is mounted a spring-actuated motor, generally designated 3,which may be of any well known or conventional type. As illustrated,

The pawl 9 is pivotally mounted at I4 so as to;

oscillate about the pivotal axis pursuant to rotation of the escapementwheel 8 under the influence of the spring 4. The parts of the motor,with the exception of the escapement wheel 8 and pawl 53, are preferablyinterposed between the plate I and a plate l5, forwardly spacedrelatively thereto, said plates constituting frames for the motor works.The escapement wheel 8 and pawl 9 are positioned forwardly of the frameI5, and on this same side of the frame is arranged a gong I6, whichmaybe mounted in any suitable manner, as on the post ll. Fixedly secured tothe pawl 9, for oscillation therewith, is a striker or clapper l8,adapted to strike the gong it when the escapementis actuated by thespring motor. The power to drive the motor may be stored in the spring 4by winding the shaft l9 with a key, in the conventional manner. Theratchet 20, pawl 2| and spring arm 22 serve to establish an operativeconnection between the wind shaft and the gear train, while permittingthe wind shaft to be rotated to wind up the spring without producingmotion in the gear train during the winding operation.

In order to set the alarm and restrain the same from operation until afire occurs, I provide a detent lever 23, which is pivotally mounted onthe frame plate 15, as at 24. The free end 25 of the detent lever isdisposed for operative engagement with the end l2 of the arm H] of theheads 33 on the ends thereof.

escapement pawl 9, when the detent lever is pivotally shifted in onedirection. When so shifted, the detent lever rocks the pawl 9 in aclockwise direction, as viewed in Figure 1, causing the end l3 of thepawl arm H to engage and lock the escapement wheel 8 against rotation.

The detent lever 23 is extended rearwardly, as at 28, towards the plateI, and thence upwardly adjacent to the front of the plate I, as at 27.Adjacent to the upper extremity of the detent lever, as at 28, isconnected one end of a helical spring 29, the opposite end of saidspring being fixedly connected to a static-nary post or lug 3!), whichextends forwardly from the plate. The

, spring is so tensioned as to normally urge the detent lever in aclockwise direction, whereby to withdraw the end 25 of the lever awayfrom engagement with the end l2 of the pawl arm Ill and thus free theescapement and permit the motor to drive the same for sounding the gongl6.

In order to restrain the detent lever from being shifted under the urgeof the spring 29, I provide a fusible link, generally designated 3!. Theopposite ends of the link 3! are respectively adapted to engage thedetent lever and a fixed stud or post 32. For convenience of replacementof the fusible links, the links may be made up in standard lengths andprovided with knobs or The post or lug 32 is slotted so that when thecorresponding end of the link is inserted into the slot, the head 33will prevent the link from being drawn through the slot, as will beobvious from inspection of the drawing. A lug or post 36, generallysimilar in form to lug 32, may be provided on the detent lever adjacentits upper end to facilitate the detachable connection of the oppositeend of the fusible link with the detent lever. 35 designates the slot inthe lug 34 which receives the end of the fusible link 3!, as best viewedin Figure 2.

A stop lug 36 is preferably provided soas to limit the movement of thedetent lever in a counter-clockwise direction, as viewed in Figure 1,and thereby prevent undue strain from being inadvertently placed uponthe escapement or other parts of the mechanism, during setting of thealarm, as in replacing the fusible links. The lug 36, as well as thelugs 32 and 30, may be formed by stamping the same out of the materialof the plate I, and bending the same forwardly, the plate beingpreferably made of relatively thin gauge metal.

The operation of the mechanism just described should be clear from theforegoing, and may be briefly summarized as follows: Assuming that thespring motor has been wound, the alarm may be set and restrained fromoperating by shifting the detent lever 23 in a counter-clockwisedirection, as viewed in Figure 1, and inserting the opposite ends of afusible link 31 in the respective lugs 32 and 34. This places the spring28 under tension normally tending to urge the detent lever in aclockwise direction, Should a fire break out, the heat will melt thelink 3! and thereby free the detent lever so as to cause it to beshifted in a clockwise direction, as viewed in Figure 1, by the spring29, thereby freeing the escapement and allowing the latter to be drivenby the clockwork motor. In the operation of the escapement, the pawl 9and clapper H? are oscillated on the pivot l4, resulting in engagementof the clapper with the gong it, sounding an audible alarm.

If for some reason the alarm should be set off inadvertently, causingthe spring motor to run down so as to become inoperative for sounding analarm, an indicator, preferably of a visible character, will bepresented to view as a warning that the alarm unit should be rewound andreset. The indicator also serves as a reminder if the resetting of thealarm unit is overloaded after an alarm has been given pursuant to thebreaking out of a fire. As illustrated, the indicating means embodies asignal arm 31, having one end pivotally connected, as at 38, with thedetent lever, and its opposite end adapted to be projected beyond oneside of the plate I. By coloring the outer end of the signal arm with adistinctive color, it will readily attract attention as soon as it isprojected. 39 designates a guide for guiding the movementof the signalarm 3'! as it is projected laterally to the position indicated by thedotted lines in Figure 1, pursuant to tripping of the detent lever 23 toallow itto be urged to the dotted line position shown in Figure 1, underthe influence of the spring 29.

It will be readily understood that the mechanism just describedconstitutes a self-contained alarm unit which may be installed withoutre- 1 quiring any auxiliary source of power or auxiliary external parts.However, there may be occasions where it is desired to cause a signal tobe given at some point remotely distant from the alarm unit, when a firebreaks out and the alarm unit trips. To this end, I have provided a pairof electrical contacts :38 and il, which are normally spaced apart, butarranged to be engaged, preferably by the detent lever 23, when thelever swings towards the dotted line position of Figure 1, upon ruptureof the fusible link 3|. When so engaged, the switch contacts are adaptedto close an electrical circuit, diagrammatically designated 42, saidcircuit embodying one or more signalling devices such as a signal light,bell, buzzer, or the like. For purposes of illustration, I have shown abell 43 in the circuit 42, and it is to be understood that this hell orother signal device may be located some distance away from the gong l 6,so that in case the sound of the gong it should not attract attention,the signal device 53 may additionally be relied upon to give the alarm.The power source for energizing the signal device 43 may be of anysuitable type, as for example, a transformer 4Q, operatively connected 0with a service main 45. For the purpose of facilitating the connectionof the contacts 40 and 4E in the auxiliary circuit 42, I provide a pairof terminals 46, which may be mounted upon the base plate I in anysuitable manner, and in- 1.

sulated therefrom, to which the conductors 41 and 48 leading to therespective contacts 4| and 4! may be secured.

As a specific example of a practical application of the alarm unit touse in an ordinary dwelling, the unit may be installed in the basementof the building, say near the furnace or heating system, where a fire ismost likely to start. The gong l6 should be of such size that the soundthereof may be heard at a considerable distance. However, the occupantsof the building may not be able to hear the gong if they should happento be on the upper floors of the building, as for instance, afterretiring to their bed chambers which may be located a considerabledistance from the gong It. Accordingly, the signal device or devices 43,if located somewhere in the building on one or more of the upper floors,or in one or more of the bed chambers, may be relied upon to give analarm signal even if the sound of the gong [6 should not be heard. Inmany homes, the building is wired for service signals, embodying one ormore buzzer or bell circuits, and it is to be understood that thiscircuit, or circuits, may be utilized as the auxiliary circuitrepresented diagramatically by the circuit designated 42 in Figure l, inwhich event, it will only be necessary to connect the existing circuitto the terminals 46 so as to place the circuit under the control of theswitch contacts so and 4!.

To protect the alarm mechanism, and toenhance the appearance of theunit, I preferably provide a cover or housing, generally designated 49,which is substantially box-like in form, with its rear side open so thatthe same may be placed over the mechanism and telescoped onto theforwardly projecting flanges 50 of the base plate I. The frictionbetween the marginal edges of the cover and the flange B ordinarily isadequate to retain the cover in position, but if desired, any suitablesecuring means may be utilized to releasably fasten the cover to thebase so that it may be conveniently removed to give access to the alarmmechanism, as when it is desired to replace the fusible link, or to windup the spring, after an alarm has been given.

The cover 59 is preferably provided with louvers 5| in order to enablethe fusible element to be subjected to the surrounding atmospherictemperatures without appreciable lag, inasmuch as it is essential thatthe fusible element be ruptured quickly in the event a fire should breakout. I also perferably provide grill-like openings 52 in the front wallof the casing or cover 49 so that the sound of the gong may be heard ata substantial distance away from the alarm unit. The top wall of thecasing or cover 69 is recessed, as at 53, and pivotally secured to thiswall is a handle or bail 5 1 which may be utilized to suspend the alarmunit from a suitable support such as a hook or nail, where such amounting is preferred in lieu of screws or other fastenings which areadapted to be passed through the openings 2 in the base plate 5. Thehandle 54 also serves as a convenient means for enabling the alarm unitto be carried from place to place, as desired. When not in use, thehandle may be folded down into the recess 53, to an out-of-the-wayposition, as will be obvious.

Referring now to Figure 3, I have shown a slightly modified constructionof the alarm unit which is particularly adaptable to the use of aremotely located fusible link, whereby the alarm may be set off inresponse to the rupture of the fusible link even though it may belocated at a considerable distance from the alarm mechanism. In otherwords, it is within the purview of my invention to substitute for thefusible link SI of Figure 1, a flexible member such as a cable or wire55, which may be extended through other rooms of the building, or evento other buildings, at quite some distance from the alarm unit. In theflexible member 55, may be inserted one or more fusible elements 5%,which will be located within the zone or zones which are tobe protectedby the alarm apparatus. For example, if the alarm unit is mounted in thebasement of a dwelling, the flexible member 55 may be extended to theupper floors, or out to the garage or other outlying buildings, andthere would be a fusible element inserted in those portions of theflexible member which extend to the other floors or to the garage. Ofcourse, the arrangement of the flexible members and fusible elements maybe widely varied according to the particular conditions presented for agiven installation. Now it will be understood that the distal end of theflexible element 56 will be fixedly secured so that the detent lever 23will be restrained against the urge of the spring 29, when the alarm isset, the

fusible elements 56 being located intermediate.

the detent lever and the fixed end of the flexible element. In adaptingthe alarm unit to the use of a long flexible element such as the wire orcable 55, I preferably mount a pulley 5? on the base plate l adjacent tothe upper lefthand corner thereof, as viewed in Figure 1,, over whichpulley the flexible member may be trained. An opening 53 is provided inthe base plate 6 so that the flexible member may be extended rearwardlyfrom the alarm unit. A similar opening 59 in the side flange 5!] permitsthe flexible member to be extended laterally from the alarm unit shouldsuch an arrangement be more suitable. It will be understood, of course,that the cover or casing 49 is slotted so as not to obstruct the opening59, and the opposite side wall of the cover is also slotted or notchedout so as to allow the signal arm 3'? to be projected laterally to thedotted line position indicated in Figure 1 when the alarm is set off. Itwill be noted'that the pulley 51 extends forwardly so that when theflexible member 55- is trained thereabout, the flexible member willclear the lug-32 which is'not used when the long cable or-wire 55 is inuse. The construction illustrated in Figure 3'is therefore adapted forthe alternative arrangement of the fusible elements, as just described,or the arrangement pr viously described and illustrated in Figure 1. Theother mechanism of the Figure 3 construction may be the same asillustrated in Figures 1 and 2. v

Instead of moimting the gong l6 as illustrated in Figures 1 and 2, itwill be obvious that the same may be positioned more nearly over thecenter of the spring motor, with the striker or clapper adapted toengage the inner surface of the gong, in which event, the alarm unit maybe shortened in length to provide a more compact structure. By mountingthe various elements constituting the alarm mechanism, all on the baseplate I, the unit will give satisfactory service even if the casing orhousing 49 is not employed, or is removed. However, by reason of thefact that the louvers 5| in the casing are inclined downwardly, thefusible element 3| will rupture a little quicker responsive to the heatof a fire, when the cover is mounted on the base, due to the naturaltendency of the heated air in the vicinity of the alarm unit to rise,and thereby be deflected by the louvers intothe interior of the casing.I

Because of the simplicity and comparatively low cost of my improvedalarm unit, it is entirely practical and feasible to employ several ofthe units in the same building. Preferably, there should be a unitmounted in each vertical shaft or opening in the building, as forexample, in each dumb-waiter shaft, elevator shaft, and stairway shaft.Also, by providing a unit at or adjacent to each exit, the sounding ofan alarm will indicate to the occupants of the building that there is alikelihood that the exit is blocked by the fire, when the alarm istripped.

While the specific details of construction have been herein shown anddescribed, the invention is not confined thereto, as changes andalterations may be made without departing from the spirit thereof asdefined. by the appended claims. Having thus described my invention,what I claim as new and desire to secure by Letters Patent is- 1. In analarm apparatus of the class described, the combination with aspring-actuated motor including a toothed escapement wheel and apivotally mounted escapement pawl having a plurality of arms coactingwith said escapement wheel respectively at opposite sides thereof, agong, and a clapper mounted for oscillating movement responsive topivotal movement of the escapement pawl, of a detent lever pivotallymounted intermediate its ends and having one end adapted to engage onearm of the escapement pawl when the lever is pivoted in one direction,whereby to rock the escapement pawl on its pivot and move the other armof the pawl into locking engagement with the escapement wheel andthereby maintain the motor and clapper inactive, means yieldably urgingsaid detent lever in a direction tending to release said escapementwheel so that the motor may operate the clapper and sound the gong, andmeans including a fusible element for restraining the detent leveragainst movement under the urge of said yieldable means aforesaid.

2. In an alarm apparatus of the class described, the combination with aspring-actuated motor including a toothed escapementwheel and apivotally mounted escapement pawl coacting with said escapement wheel, agong, and a clapper mounted for oscillating movement responsive topivotal movement of the escapement pawl, of a detent lever pivotallymounted intermediate its ends and having one end adapted to engage theescapement pawl when the lever is pivoted in one direction, whereby tomaintain the pawl in looking engagement with the escapement wheel andthereby maintain the motor and clapper inactive, spring means having oneend fixed to a stationary part of the apparatus and. the other endconnected with the detent lever adjacent to the end of the latter on theside of the pivotal axis of the detent lever opposite to thepawl-engaging end for yieldably urging said detent lever in a directiontending to release said escapement wheel so that the motor may operatethe clapper and sound the gong, and

means including a fusible element for restraining the detent leveragainst movement under the urge of said yieldable means aforesaid, saidlast named means having one end fixed to a relatively stationary partand its opposite end connected with the end of the detent lever to whichthe spring means is connected and extending therefrom in opposedrelation to the spring means with the fusible element intermediate thefixed end and the detent lever.

3. In an alarm apparatus of the class described, the combination with aspring-actuated tionary part of the apparatus and the other endconnected with the detentlever adjacent to the end of the latteropposite to the pawl-engaging end for yieldably urging said detent leverin a direction tending to release said escapement wheel so that themotor may operate the clapper and sound the gong, and means including afusible element 'for restraining the detent lever against movement underthe urge of said yieldable means aforesaid, said last named means havingone end fixed toa relatively stationary part and its opposite endconnected with the end of the detent lever to which the spring means isconnected and extending therefrom in opposed relation to the springmeans with the fusible element intermediate the fixed end and the detentlever, and the detent lever having a slotted part forming an open-endedrecess for receiving and establishing interlocking engagement with oneend of the fusible element.

JOHN Y. LAMBERT.

